Prevent GH_AW_TOOLS_META_JSON expression-size overflows in compiled workflows

actions/setup/js/generate_safe_outputs_tools.cjs

@@ -201,6 +201,25 @@ function applyAssignMilestoneAlternativeRequirements(tool) {
   schema.anyOf = [{ required: ["milestone_number"] }, { required: ["milestone_title"] }];
 }
 
+/**
+ * Resolve ${ENV_VAR} placeholders inside a JSON string from process.env.
+ * Replacement values are escaped as JSON string content so quotes, backslashes, and
+ * newlines in the resolved value do not corrupt the surrounding JSON document.
+ * Unresolved placeholders are left unchanged.
+ * @param {string} value
+ * @returns {string}
+ */
+function resolveEnvStringPlaceholders(value) {
+  return value.replace(/\$\{([A-Z_][A-Z0-9_]*)\}/g, (match, envName) => {
+    const envValue = process.env[envName];
+    if (envValue === undefined) {
+      return match;
+    }
+    // JSON.stringify wraps the value in quotes; strip them to get escaped string content.
+    return JSON.stringify(envValue).slice(1, -1);
+  });
+}
+
 async function main() {
   const toolsSourcePath = process.env.GH_AW_SAFE_OUTPUTS_TOOLS_SOURCE_PATH || `${process.env.RUNNER_TEMP}/gh-aw/actions/safe_outputs_tools.json`;
   const configPath = process.env.GH_AW_SAFE_OUTPUTS_CONFIG_PATH || `${process.env.RUNNER_TEMP}/gh-aw/safeoutputs/config.json`;
@@ -210,7 +229,7 @@ async function main() {
   // Write JSON payloads from env vars if provided (replaces heredoc-based file writing)
   if (process.env.GH_AW_TOOLS_META_JSON) {
     try {
-      fs.writeFileSync(toolsMetaPath, process.env.GH_AW_TOOLS_META_JSON);
+      fs.writeFileSync(toolsMetaPath, resolveEnvStringPlaceholders(process.env.GH_AW_TOOLS_META_JSON));
     } catch (err) {
       throw new Error(`${ERR_SYSTEM}: Failed to write file ${toolsMetaPath}: ${getErrorMessage(err)}`, { cause: err });
     }

actions/setup/js/generate_safe_outputs_tools.test.cjs

@@ -232,6 +232,95 @@ describe("generate_safe_outputs_tools", () => {
     expect(result).toHaveLength(0);
   });
 
+  it("resolves env placeholders in GH_AW_TOOLS_META_JSON", () => {
+    fs.writeFileSync(configPath, JSON.stringify({ create_issue: { max: 1 } }));
+    const metaFromEnv = JSON.stringify({
+      description_suffixes: {
+        create_issue: " TARGET: ${GH_AW_INPUT_TARGET_REPO}",
+      },
+      repo_params: {},
+      dynamic_tools: [],
+    });
+
+    runScript({
+      GH_AW_TOOLS_META_JSON: metaFromEnv,
+      GH_AW_INPUT_TARGET_REPO: "github/gh-aw",
+    });
+
+    const result = JSON.parse(fs.readFileSync(outputPath, "utf8"));
+    const createIssueTool = result.find((/** @type {{name: string, description: string}} */ t) => t.name === "create_issue");
+    expect(createIssueTool).toBeDefined();
+    expect(createIssueTool.description).toContain("TARGET: github/gh-aw");
+  });
+
+  it("resolves multiple distinct env placeholders in GH_AW_TOOLS_META_JSON", () => {
+    fs.writeFileSync(configPath, JSON.stringify({ create_issue: { max: 1 } }));
+    const metaFromEnv = JSON.stringify({
+      description_suffixes: {
+        create_issue: " TARGET: ${GH_AW_INPUT_TARGET_REPO} OWNER: ${GH_AW_GITHUB_REPOSITORY_OWNER}",
+      },
+      repo_params: {},
+      dynamic_tools: [],
+    });
+
+    runScript({
+      GH_AW_TOOLS_META_JSON: metaFromEnv,
+      GH_AW_INPUT_TARGET_REPO: "github/gh-aw",
+      GH_AW_GITHUB_REPOSITORY_OWNER: "github",
+    });
+
+    const result = JSON.parse(fs.readFileSync(outputPath, "utf8"));
+    const createIssueTool = result.find((/** @type {{name: string, description: string}} */ t) => t.name === "create_issue");
+    expect(createIssueTool).toBeDefined();
+    expect(createIssueTool.description).toContain("TARGET: github/gh-aw");
+    expect(createIssueTool.description).toContain("OWNER: github");
+  });
+
+  it("leaves unresolved placeholders in GH_AW_TOOLS_META_JSON unchanged", () => {
+    fs.writeFileSync(configPath, JSON.stringify({ create_issue: { max: 1 } }));
+    const metaFromEnv = JSON.stringify({
+      description_suffixes: {
+        create_issue: " TARGET: ${GH_AW_INPUT_MISSING}",
+      },
+      repo_params: {},
+      dynamic_tools: [],
+    });
+
+    runScript({
+      GH_AW_TOOLS_META_JSON: metaFromEnv,
+    });
+
+    const result = JSON.parse(fs.readFileSync(outputPath, "utf8"));
+    const createIssueTool = result.find((/** @type {{name: string, description: string}} */ t) => t.name === "create_issue");
+    expect(createIssueTool).toBeDefined();
+    expect(createIssueTool.description).toContain("TARGET: ${GH_AW_INPUT_MISSING}");
+  });
+
+  it("escapes quotes, backslashes, and newlines when resolving GH_AW_TOOLS_META_JSON placeholders", () => {
+    fs.writeFileSync(configPath, JSON.stringify({ create_issue: { max: 1 } }));
+    const metaFromEnv = JSON.stringify({
+      description_suffixes: {
+        create_issue: " TARGET: ${GH_AW_INPUT_TARGET_REPO}",
+      },
+      repo_params: {},
+      dynamic_tools: [],
+    });
+
+    runScript({
+      GH_AW_TOOLS_META_JSON: metaFromEnv,
+      GH_AW_INPUT_TARGET_REPO: 'a"b\\c\nd',
+    });
+
+    // The written tools_meta.json must remain valid JSON despite the unsafe characters.
+    const writtenMeta = JSON.parse(fs.readFileSync(toolsMetaPath, "utf8"));
+    expect(writtenMeta.description_suffixes.create_issue).toContain('a"b\\c\nd');
+
+    const result = JSON.parse(fs.readFileSync(outputPath, "utf8"));
+    const createIssueTool = result.find((/** @type {{name: string, description: string}} */ t) => t.name === "create_issue");
+    expect(createIssueTool).toBeDefined();
+    expect(createIssueTool.description).toContain('TARGET: a"b\\c\nd');
+  });
+
   it("ignores non-tool config keys when filtering", () => {
     // dispatch_workflow and max_bot_mentions are not tool names in source file
     fs.writeFileSync(

eslint-factory/src/rules/no-exec-interpolated-command.test.ts

@@ -179,7 +179,7 @@ describe("no-exec-interpolated-command", () => {
         },
         // execApi parameter-alias with identifier args (still array-shaped by convention) — flagged
         {
-          code: "function run(execApi, branchName) { execApi.exec(\"git checkout \" + branchName, args); }",
+          code: 'function run(execApi, branchName) { execApi.exec("git checkout " + branchName, args); }',
           errors: [{ messageId: "interpolatedCommand", data: { kind: "dynamic string concatenation", method: "exec" } }],
         },
       ],